Soul Shards: The Old Ways
Soul Shards is an engaging modification that allows players to collect creature souls into special crystals. These energy-filled gems can then be used to create soul cages that automatically summon corresponding mobs.
How the System Works
To obtain a shard, you need to build a small ritual structure and activate its center with a diamond. The creation process is demonstrated in the following animation:

The first mob killed with a shard in your inventory permanently binds the crystal to that type of creature. From that moment on, the shard will only absorb souls of exactly these beings. To speed up energy accumulation, you can interact with spawners of corresponding mobs — this instantly adds 200 souls (configurable value).
Features for Pack Creators
Starting from version 1.8, the mod is distributed under the MIT license, providing complete freedom of use in any modifications and packs.
Important Information
Since February 29, 2016, development has been entirely handled by TehNut, to whom all questions and suggestions should be directed.
Version 1.7.10 Features
In this version, the mod returns to its roots with the reimplementation of the Soul Forge and Corrupted Essence. Unlike the original concept, now almost every aspect of the mod can be customized to your preferences.
Don't like the smelting time for Soulium or shards? Change it in the configuration file. Want to use the old mechanics? Enable easy mode, and the system will revert to the previous method of activation with glowstone (though this option is not recommended and will gradually be removed).
The mod can be freely used in packs provided that no element is placed behind paywalls or advertising links, and the mod itself is not distributed separately.